Animating Material Nodes in the Game Engine
The easiest solution is to use Object Color. This can be accessed both by python and by the node editor, and gives you access to three per-object values.

In UPBGE you can access object color using the ObjectData node:


In normal BGE you have to create a shadeless white material with object color enabled. Remember to make the diffuse color white, otherwise the color is multiplied (by default) by 0.8!



Slightly unclear from the image is that there are two materials: the shadeless object color one, and the node one.